Astudy was conducted to determine the effectiveness of varying amounts of vitamin c in reducing the number of common colds. a survey of 450 people provided the following information:

daily amount of vitamin c taken
none 500 mg 1000 mg
no colds 57 26 17
at least one cold 223 84 43

what conclusion can be made?

a.) approximately 64% of the people that had at least one cold did not take vitamin c.
b.) the data proves that vitamin c has no effect on the number of common colds.
c.) the data proves that vitamin c reduces the number of common colds.
d.) approximately 50% of the people that had at least one cold did not take vitamin c.
e.) since common colds are caused by viruses, there is no reason to conclude that vitamin c could have any effect.

8000 + 8800 + 8000 + 8 million + 80 trillion + another a katrillion equals

I've been working on this for a few days and i just don't understand, it's due in a few hours. you. the direction of a vector is defined as the angle of the vector in relation to a horizontal line. as a standard, this angle is measured counterclockwise from the positive x-axis. the direction or angle of v in the diagram is α. part a: how can you use trigonometric ratios to calculate the direction α of a general vector v = < x, y> similar to the diagram? part b suppose that vector v lies in quadrant ii, quadrant iii, or quadrant iv. how can you use trigonometric ratios to calculate the direction (i.e., angle) of the vector in each of these quadrants with respect to the positive x-axis? the angle between the vector and the positive x-axis will be greater than 90 degrees in each case. part c now try a numerical problem. what is the direction of the vector w = < -1, 6 > ?

Proving the congruent supplements theorem